The survey-and-carrier hull. A ring-framed polymer hull rated to 100 m that runs the long leg, carries one neutral 20 kg cartridge and brings its data home.
A survey hull that doubles as a carrier bus: range and payload sit at this end of the Water family, and the quiet close work goes to the creeper it carries.
A ring-framed Ø240 mm polymer cylinder is the only volume at one atmosphere. Everything the water touches first is a free-flooded moulded shell, so the hard engineering sits in one simple part that is proof-tested before its first wet use.
A shrouded low-RPM screw and a 2.0 kWh pack give 139 km at 0.91 m/s with the inertial navigator and the Doppler log live, in still water. The quiet last kilometre belongs to the creeper it carries.
A 20 kg / 20 L bay at the centre of buoyancy behind an interface defined once. Every cartridge is neutral by rule, so fitting or releasing one leaves the trim where it was.
No warhead, no fuze and no energetic material in any cartridge, and no radio or GPS aboard. The acoustic modem is a sparse check-in and never a control channel.
The selected baseline of CS-310, grouped the way an integration engineer reads it: form, pressure hull, collapse, mass, drive, endurance, bay, crossings, guidance and recovery.
Vehicle and arrangementPressure hullCollapse and safety factorsMass and displacementPropulsion, trim and powerDrag and enduranceWet bay and cartridgesPressure-boundary crossingsGuidance, autonomy and communicationsAbort, handling and recoveryConstruction
| Parameter | Value | Basis |
|---|---|---|
| Form | Torpedo-form body of revolution | a dry pressure hull inside a free-flooded moulded fairing |
| Overall length | 2.60 m | design value, the selected baseline |
| Fairing diameter | Ø345 mm | design value; the widest section of the vehicle |
| Fineness ratio | 7.5 | calculated, 2,600 mm over 345 mm |
| Wetted surface | 2.94 m² | calculated; fairing, nose, tail and fins |
| Control surfaces | Four cruciform stern planes | top, bottom, port and starboard; effective with way on |
| Dry core, forward to aft | Variable-ballast tank and pump · battery pack · moving-mass trim rail · avionics, INS and compute · thruster motor and drive electronics | the general arrangement |
| Outside the pressure hull | Acoustic-modem transducer · down-looking DVL · ventral wet bay · ventral drop weight · shrouded propeller | the general arrangement |
| Pressure-hull material | Glass-filled nylon | design value, the selected baseline |
| Fairing | Free-flooded moulded polymer, eligible for recycled PET | nose, mid and tail shells; no pressure differential and no structural load |
| Parameter | Value | Basis |
|---|---|---|
| Outer diameter | Ø240 mm | design value, the selected baseline |
| Wall | 12 mm | design value, the selected baseline |
| Cylinder length | 1,500 mm | design value, the selected baseline |
| End closures | Hemispherical, 8 mm | design value; 6 mm closures would govern the hull |
| Ring frames | Four internal frames, 40 × 25 mm section | design value, the selected baseline |
| Frame pitch | 300 mm | design value, the selected baseline |
| Critical length | 1,224 mm | calculated; each 300 mm bay is a short cylinder |
| Clear bore between frames | Ø216 mm | calculated from the wall |
| Clear bore at a frame | Ø166 mm | calculated from the wall and the frame depth |
| Proof test | Every hull, hydrostatically, before its first wet use | a rule on every hull built |
| Parameter | Value | Basis |
|---|---|---|
| Design depth | 100 m | the littoral and continental-shelf work band |
| External pressure at 100 m | 1.006 MPa | calculated, seawater |
| Knock-downs in every collapse figure | Creep ×0.50 on modulus · ovality ×0.70 on the cylinder · ×0.25 on the spherical closures | the method every collapse figure on this sheet is calculated with |
| Governing mode | Inter-bay shell buckling | Windenburg–Trilling short-cylinder relation |
| Governing collapse pressure | 2.73 MPa | calculated |
| Nominal collapse depth | 271 m | calculated from the governing pressure |
| Safety factor at 100 m | 2.71 | calculated |
| Safety factor at 50 m | 5.42 | calculated |
| General instability, shell and frames | 2.84 MPa · safety factor 2.82 | calculated, Bryant relation at n = 2; clear of the governing mode |
| End closures, 8 mm | 4.11 MPa · safety factor 4.09 | calculated, classical sphere relation; clear of the governing mode |
| Parameter | Value | Basis |
|---|---|---|
| Pressure hull, 8 mm closures and four frames | 24.55 kg · 75.10 L | calculated, the mass and displaced-volume ledger |
| Fairing, control surfaces and thruster duct | 15.89 kg · 11.77 L | calculated; free-flooded |
| Battery pack, 2.0 kWh | 14.29 kg | calculated, packaged pack; inside the hull |
| Thruster motor and drive electronics | 3.00 kg | ledger allocation; inside the hull |
| Propeller, shaft and coupling rotor | 1.00 kg · 0.40 L | ledger allocation; wet side |
| Four control-plane actuators and linkages | 2.50 kg · 1.50 L | ledger allocation; wet side |
| Avionics, INS and compute | 4.00 kg | ledger allocation; inside the hull |
| DVL and acoustic-modem transducers | 2.00 kg · 1.20 L | ledger allocation; wet side |
| Variable-ballast machinery | 4.00 kg | ledger allocation; dry, inside the hull |
| Ballast water at half fill | 2.50 kg | the neutral datum |
| Moving-mass trim rail | 1.20 kg | ledger allocation; inside the hull |
| Penetrators, harness and connectors | 3.00 kg · 0.50 L | ledger allocation |
| Drop-weight abort, cast iron | 3.00 kg · 0.38 L | ledger allocation; wet side |
| Dry mass | 80.93 kg · 90.85 L | calculated, the sum of the ledger |
| Displacement in seawater | 93.12 kg | calculated |
| Fixed trim ballast and reserve | 12.19 kg | calculated; 13% of displacement |
| Payload cartridge | 20.00 kg | neutral by interface rule |
| Vehicle wet displacement | 113.12 kg | calculated, with the cartridge fitted |
| Fresh-to-salt buoyancy swing | 2.27 kg | calculated on this displacement |
| Variable-ballast authority | ±3 kg | requirement; set above the fresh-to-salt swing |
| Parameter | Value | Basis |
|---|---|---|
| Propulsor | One shrouded low-RPM propeller in a duct | low tip speed and low blade loading; the duct guards against snags |
| Motor | Brushless motor inside the pressure hull | turns the propeller through a magnetic coupling |
| Coupling | Magnetic, torque only | no dynamic seal and no crossing of the pressure boundary |
| Coupling loss at best range | ~1.1 W · about 0.8% of range | calculated: 8% of ~14.3 W shaft power at 0.91 m/s, against a 47 W total budget |
| Battery | 2.0 kWh | design value; inside the pressure hull |
| Pitch trim | Battery on a lead-screw moving-mass rail | static pitch without spending control-plane authority |
| Depth and density trim | Pumped variable-ballast tank inside the hull | density change and payload-release compensation |
| Station-keeping | Tunnel-thruster hover module, about 6 L of the bay | bolt-in; fitted on the missions that hold station |
| Parameter | Value | Basis |
|---|---|---|
| Drag model | ITTC-57 friction line × form factor 1.25 × appendage factor 1.30 | over 2.94 m² wetted at a 2.60 m reference length |
| Drag area at 1.5 m/s | 0.01802 m² | calculated |
| Equivalent frontal drag coefficient | 0.193 | calculated, on the fairing's frontal area |
| Hotel load, INS and DVL live | 30 W | the load the Tier 3 endurance figures are calculated at |
| Hotel load, preset dead-reckoning | 6 W | the load the Tier 1 endurance figures are calculated at |
| Best range, INS and DVL live | 0.91 m/s → 42.7 h, 139 km | calculated on 2.0 kWh at a propulsive efficiency of 0.45, still water |
| Passage speed, INS and DVL live | 1.50 m/s → 20.1 h, 108.8 km | calculated, still water |
| Best range, preset dead-reckoning | 0.51 m/s → 212.8 h, 391 km | calculated, still water |
| Into a 0.25 m/s current | Holds 1.06 m/s → 0.81 m/s over the ground, 104 km | calculated, speed re-optimized against the set; 75% of still-water range |
| Into a 0.50 m/s current | Holds 1.26 m/s → 0.76 m/s over the ground, 75 km | calculated, speed re-optimized against the set; 54% of still-water range |
| Representative emplacement leg | 15 km out and 15 km back: 9.2 h, 22% of the battery | calculated at 0.91 m/s, still water |
| Parameter | Value | Basis |
|---|---|---|
| Bay | Free-flooded, ventral, at the centre of buoyancy | a release disturbs trim minimally |
| Bay length | ~700 mm | design value |
| Cartridge envelope | 20 kg / 20 L, nominal | one cartridge at a time |
| Cartridge buoyancy | Neutral, ±1 kg in seawater | interface rule; each cartridge is ballasted at build |
| Interface | Mount rails · wet-mate connector for power and data · retention and release · buoyancy bookkeeping | defined once, so a new cartridge is tooling rather than a redesign |
| Cartridges | Seabed sensor node · acoustic relay node · environmental sampler · inspection package · emplace and retrieve · one CS-320 | non-kinetic, by rule |
| CS-320 in the bay | 16.34 kg / 15.95 L: 18% margin on mass, 20% on volume | calculated against the bay envelope |
| Release transient | Zero | every cartridge is neutral by rule |
| Node settling offset | Roughly 50 m downstream | released at 0.91 m/s over a 30 m water column, sinking at an order of 0.5 m/s |
| Parameter | Value | Basis |
|---|---|---|
| Electrical crossings | 5, from 10 on a naive layout | the selected harness layout; each crossing is a leak path and a pressure-test item |
| Shore umbilical | Charge and data | blanked in the water |
| Tail multi-way | Four plane actuators, power and position feedback | one crossing for all four |
| DVL transducer | The down-looking Doppler velocity log | one crossing |
| Acoustic-modem transducer | The sparse check-in link | one crossing |
| Payload-bay wet-mate | Power, data and the release command | the cartridge interface |
| Thruster drive | No crossing | magnetic coupling, torque only |
| Parameter | Value | Basis |
|---|---|---|
| Tier 1 | Preset dead-reckoning | magnetic heading, depth cell, water-speed estimate and time |
| Tier 2 | Fibre-guided | a person in the loop over optical fibre from a payout spool |
| Tier 3 | Inertial navigation corrected by a Doppler velocity log | bottom lock; bought-in and export-gated in its own right |
| Radio and GPS | None aboard | RF and GPS do not penetrate seawater |
| Acoustic modem | Check-in, abort and retask | sparse by design and never a control channel; silent-running segments are a planned mode |
| Mission authority | Pre-planned mission in geofenced corridors | human authority held in the mission plan and the abort criteria |
| Loss of navigation confidence | Loiter or bottom-sit, then surface at a planned point | safety function |
| Communications timer lapse | Return to recovery | safety function |
| Critical fault | Drop-weight abort to the surface | safety function |
| Parameter | Value | Basis |
|---|---|---|
| Drop weight | 3.00 kg, cast iron, ventral | ledger allocation; cast iron because every abort leaves it on the seabed |
| Release | On command, on timer lapse or on loss of power | the weight goes and the vehicle rises |
| Recovery | A planned rendezvous at the surface; the drop weight off-nominal | the hull, the battery and the data come home |
| Handling | Two people, on a dolly or a davit | the ~113 kg class; not an unaided lift |
| Launch points | Shore, pier or vessel of opportunity | no dedicated mothership required |
| Shore support | Battery charging and mission upload before the dive; data offload after | over the shore umbilical |
| Parameter | Value | Basis |
|---|---|---|
| Non-metallic posture | Polymer pressure hull and polymer fairing | costs about 2.3 kg, roughly 2% of displacement, against an unstiffened aluminium hull sized to the same safety factor |
| Tooling | Moulds cut on the fleet's own 5-axis die shop | fairing and non-structural mouldings |
Two bodies, and only one of them is dry. The fairing gives the vehicle its shape and floods; the cylinder inside it is the one part built to hold out the sea.
A glass-filled nylon cylinder with 8 mm hemispherical closures and four internal ring frames at 300 mm pitch. It holds the ballast pump, the battery, the avionics and the thruster motor at one atmosphere.
Nose, mid and tail shells flood freely and carry no pressure load, so they are light, inexpensive and shaped for drag. Unloaded parts are eligible for recycled PET.
A flooded bay about 700 mm long that takes one nominal 20 kg / 20 L cartridge behind one interface. A release from the centre of buoyancy disturbs trim minimally.
The vehicle is 2.60 m overall over the Ø345 mm fairing, a fineness ratio of 7.5. Inside the dry core the variable-ballast tank and pump sit forward, then the battery pack and the moving-mass trim rail, then the avionics, inertial navigator and compute, with the thruster motor and its drive at the stern closure. Outside it, the acoustic-modem transducer sits on top and a down-looking Doppler velocity log below, the wet bay and the drop weight sit ventrally, and four cruciform stern planes and a shrouded propeller close the tail.
Putting the whole pressure problem into one tube with two end caps is a manufacturing decision as much as a structural one. The fairing and the other non-structural mouldings come off the fleet's own tooling, and the one part that answers to depth is proof-tested hydrostatically before its first wet use.
External pressure at 100 m is 1.006 MPa. Collapse resistance follows stiffness rather than strength, a polymer loses stiffness under sustained load, and a real tube collapses below the perfect-geometry prediction.
Two knock-downs therefore come off every collapse figure before anything is called a pass: creep at 0.50 on the modulus and ovality at 0.70 on the pressure. Applied to a plain Ø250 mm cylinder 2.0 m long, which has a critical length of 1,425 mm and sits in the long-cylinder regime, they decide the matter.
| Plain wall, Ø250 mm | Short-term collapse | Nominal depth | After creep and ovality | Safety factor at 100 m | Result |
|---|---|---|---|---|---|
| 10 mm | 0.88 MPa | 87 m | 0.31 MPa | 0.30 | Fails outright |
| 15 mm | 2.95 MPa | 294 m | 1.03 MPa | 1.03 | Fails a safety factor of 2 |
| 19 mm | 6.00 MPa | 597 m | 2.10 MPa | 2.09 | Passes, on mass |
No plain wall reaches a safety factor of 2 at 100 m short of 19 mm, and at 19 mm the wall is eating the payload. The way out of a long-cylinder problem is to stop having a long cylinder: ring frames divide the shell into short bays, where the end restraint carries load.
Ring frames at 300 mm pitch put every bay in the short-cylinder regime. Stiffening a shell also opens a second mode, general instability of shell and frames together, and the frame has to be sized against it.
| Ring frame | Inter-bay buckling | General instability | Governing mode | Safety factor at 100 m | Result |
|---|---|---|---|---|---|
| 20 × 15 mm | 2.73 MPa | 0.74 MPa | General instability | 0.73 | Fails |
| 40 × 18 mm | 2.73 MPa | 1.52 MPa | General instability | 1.51 | Fails |
| 40 × 25 mm, selected | 2.73 MPa | 2.84 MPa | Inter-bay | 2.71 | Passes |
An under-sized frame moves the failure from one mode to another at essentially the same pressure. The same Ø240 × 12 mm shell with no frames reaches 0.60 MPa after the knock-downs, a safety factor of 0.60, so the depth rating exists because of the frames.
The closures were checked on the classical sphere relation with a 0.25 knock-down, because a spherical shell is far more sensitive to imperfection than a cylinder. At 6 mm a closure reaches 2.31 MPa and would set the rating of the whole hull below its cylinder. At 8 mm it reaches 4.11 MPa and hands the governing mode back to the cylinder, for 0.98 kg across the pair.
Shell buckling between frames on the Windenburg–Trilling short-cylinder relation. The critical length of 1,224 mm sits far beyond the 300 mm bay.
Shell and frames buckling as one assembly on the Bryant relation at n = 2, a safety factor of 2.82 at 100 m.
The 8 mm hemispherical closures on the classical sphere relation with a 0.25 knock-down, a safety factor of 4.09 at 100 m.
Collapse pressure rises as roughly (t/D)2.5 and displacement as D², so the two pull in opposite directions. Swept at a 12 mm wall with 40 × 25 mm frames at 300 mm and the battery at its packaged mass, Ø240 mm closes on geometry alone, with a 12.2 kg reserve and nothing bought in.
| Hull | Safety factor at 100 m | Hull mass | Total dry | Buoyancy | Reserve | Wet displacement | Result |
|---|---|---|---|---|---|---|---|
| Ø200 × 1,400 mm | 3.54 | 18.7 kg | 73.4 kg | 64.3 kg | −9.1 kg | 84.3 kg | Sinks |
| Ø225 × 1,500 mm | 2.98 | 22.7 kg | 78.6 kg | 83.1 kg | 4.4 kg | 103.1 kg | Closes on a thin reserve |
| Ø225 × 1,500 mm with 8 L of buoyancy | 2.98 | 22.7 kg | 80.6 kg | 91.3 kg | 10.6 kg | 111.3 kg | Closes, buying in a material class |
| Ø240 × 1,500 mm, selected | 2.71 | 24.6 kg | 80.9 kg | 93.1 kg | 12.2 kg | 113.1 kg | Closes on geometry alone |
| Ø250 × 1,800 mm | 2.51 | 30.3 kg | 88.8 kg | 116.7 kg | 27.9 kg | 136.7 kg | Over-buoyant, carries trim lead |
The Ø225 mm hull with 8 L of closed-cell buoyancy is the lower-drag vehicle, but the two closing options differ by 1.9 kg wet and 9% of frontal area, and the foam brings a material class and a hydrostatic qualification item with it. The Ø240 mm hull closes with nothing bought in, and the buoyancy-module route is kept as a quantified upgrade.
Every line of the ledger carries a mass and a displaced volume, so displacement is a sum rather than an estimate. Carrying a 20 kg payload to 100 m in polymer lands at about 113 kg: a shore crew of two with a dolly or a davit, rather than an unaided lift. The fresh-to-salt swing on this displacement is 2.27 kg, and the ±3 kg of variable-ballast authority is a requirement set above it.
The non-metallic hull has a price, and it is small. An unstiffened 6061-T6 aluminium hull sized to the same safety factor of 2 at 100 m over the full 1,500 mm needs a 6.0 mm wall and weighs 22.3 kg against the polymer hull's 24.6 kg: 2.3 kg, about 2% of displacement.
Every wire that crosses the pressure boundary is a leak path, a pressure-test item and a cost line, so the harness is laid out to remove crossings rather than to route them.
Propulsion is one low-RPM propeller in a duct that doubles as a guard against snags, at low tip speed and low blade loading. A brushless motor inside the pressure hull turns it through a magnetic coupling, so torque crosses the wall and no shaft, dynamic seal or wire does. At the 0.91 m/s best-range point the electrical propulsion draw is 16.8 W and shaft power about 14.3 W, so an 8% coupling loss is about 1.1 W against a 47 W budget, roughly 0.8% of range.
The coupling removes the motor's crossing outright, and a single tail multi-way carries all four stern-plane actuators with their power and position feedback. A naive layout needs ten crossings of the pressure boundary; this one needs five.
| Crossing | Carries | Note |
|---|---|---|
| Shore umbilical | Charge and data | Blanked in the water |
| Tail multi-way | Four plane actuators, power and position feedback | One crossing for all four |
| DVL transducer | The down-looking Doppler velocity log | Bottom lock for the top guidance tier |
| Acoustic-modem transducer | The sparse check-in link | Never a control channel |
| Payload-bay wet-mate | Power, data and the release command | The cartridge interface |
| Thruster drive | Torque only | A magnetic coupling, not a crossing |
Trim is done by moving mass. The battery rides a lead-screw rail for static pitch, which keeps control-plane authority free for manoeuvring, and a small pumped variable-ballast tank inside the hull handles density change and the compensation a payload release needs. The stern planes work only with way on, so station-keeping is bought as a bolt-in tunnel-thruster module that takes about 6 L of the bay on the missions that need it.
Drag comes from an ITTC-57 friction line with a 1.25 form factor and a 1.30 appendage factor over 2.94 m² of wetted surface, because the fairing, not the pressure hull, is the widest section. The equivalent frontal drag coefficient is 0.193.
| Speed through the water | Drag | Tier 1, 6 W hotel | Tier 1 range | Tier 3, 30 W hotel | Tier 3 range |
|---|---|---|---|---|---|
| 0.50 m/s | 2.90 N | 217.0 h | 390.6 km | 60.2 h | 108.4 km |
| 0.80 m/s | 6.71 N | 111.6 h | 321.4 km | 47.7 h | 137.4 km |
| 1.00 m/s | 10.01 N | 70.8 h | 254.9 km | 38.3 h | 137.8 km |
| 1.20 m/s | 13.90 N | 46.4 h | 200.6 km | 29.8 h | 128.8 km |
| 1.50 m/s | 20.78 N | 26.6 h | 143.5 km | 20.1 h | 108.8 km |
| 2.00 m/s | 34.96 N | 12.4 h | 89.2 km | 10.8 h | 77.7 km |
Every row is still water, on 2.0 kWh at a propulsive efficiency of 0.45. With the inertial navigator and the Doppler log live, the best-range speed is 0.91 m/s for 139 km over 42.7 h, and at that optimum the 16.8 W electrical propulsion draw is about half the 30 W hotel draw. On preset dead-reckoning with neither instrument powered, the optimum is 0.51 m/s for 391 km over 212.8 h.
Power is set by speed through the water and range by speed over the ground, and the gap is the current. Allowed to re-optimize against the set, the hull holds 1.06 m/s into 0.25 m/s for 0.81 m/s over the ground and 104 km, 75% of its still-water range, and 1.26 m/s into 0.50 m/s for 0.76 m/s and 75 km, 54%. Into an adverse current the right answer is to speed up, because time in the water costs hotel energy.
One envelope, one bay, many cartridges. The interface is defined once, as mount rails, a wet-mate connector, retention and release, and the buoyancy bookkeeping, so a new cartridge is tooling rather than a redesign.
One rule pays for itself three times: every cartridge is neutrally buoyant to ±1 kg in seawater. The vehicle trims the same whichever cartridge is fitted, a release is trim-neutral at the moment the vehicle is trying to hold position, and carrying the family's creeper becomes cheap rather than a stability problem. The cost is a fixture and a scale, because every cartridge is ballasted at build.
Passive acoustic or environmental packages for persistent harbour and approach monitoring. Released at 0.91 m/s over a 30 m water column, a node settles roughly 50 m downstream of the release point.
Extends an acoustic network without a surface vessel.
Water-quality sondes and sediment samplers: the civil work, on the same hull as the survey.
A camera or imaging-sonar cartridge for structure inspection, with the hover module fitted where the vehicle has to hold against a set.
Low-signature delivery or recovery of tags, beacons and instrumentation where a surface presence is unwanted. Export-sensitive in its own right.
The creeper closes at 16.34 kg and 15.95 L, inside the bay with 18% margin on mass and 20% on volume, and leaves on the release command the interface already carries.
The list ends there by rule rather than by omission: no warhead, no fuze, no energetic material and no terminal-effect payload, in any cartridge, in any variant, for any customer. Carriage of the creeper is a cartridge fit, not a docking system. CS-310 transits and releases, the creeper runs the last leg and surfaces at a planned point for its own recovery, and because it is neutral by rule the release transient is zero.
Under water the no-radio, no-GPS doctrine is the operating condition, because RF and GPS do not penetrate seawater. The vehicle runs a pre-planned mission in geofenced corridors, and the person holds authority at mission grain rather than joystick grain.
Mission plan, corridors and abort criteria load at the shore station over the shore umbilical, which is blanked in the water.
The vehicle loiters or sits on the bottom, then surfaces at a planned point.
The vehicle comes back to the recovery point on its own.
The drop weight goes and the vehicle rises to the surface.
The acoustic modem takes a check-in, an abort or a retask at a contact and never flies the vehicle, which is autonomous between contacts. Silent-running segments with no transmissions are a planned mode, because acoustic emissions cost signature too.
What is fitted decides the tier. A preset hull flies pre-programmed legs on heading, depth, speed through the water and time. A fibre-guided hull trails a physical thread from a payout spool with a person on the far end. The top tier is an inertial navigator corrected by a Doppler velocity log with bottom lock, bought rather than built and export-gated in its own right. The three builds are set out below.
The drop weight is a 3.00 kg cast-iron assembly on the ventral keel. On command, on timer lapse or on loss of power, the weight goes and the vehicle rises.
It is the one subsystem aboard that has to work when nothing else does, and loss of power is one of the three things that release it, so a vehicle that loses its power still ends on the surface.
The weight is cast iron rather than lead because every abort leaves it on the seabed. Recoverability is an environmental requirement and an economic one: nominal recovery is a planned rendezvous at the surface, off-nominal recovery is the weight, and either way the hull, the battery and the data come home.
From a shore, a pier or a vessel of opportunity, with no dedicated mothership. The hull is about 113 kg wet with its cartridge fitted.
The hull runs its survey lines carrying its cartridge at the centre of buoyancy, with silent-running segments where the mission calls for them.
A planned rendezvous at the surface, or the drop weight. Charging, mission upload and data offload run over the shore umbilical.
The hull, the bay and the abort are common to every build. What differs is what is fitted to navigate, and whether the bay gives 6 L to a hover module.
Pre-programmed legs on magnetic heading, a depth cell, a water-speed estimate and time, at a 6 W hotel load: best range 391 km at 0.51 m/s in still water. Position error grows with distance, so it suits short, forgiving legs.
A person in the loop over optical fibre from a payout spool, with no launch shock and low speeds. The natural build for inspection work, with its reach set by the spool's volume.
Inertial navigation corrected by a Doppler velocity log with bottom lock, at a 30 W hotel load: best range 139 km at 0.91 m/s in still water. The capable build, and the one with export treatment of its own.
Tunnel thrusters in a module that takes about 6 L of the 20 L bay, fitted for pier and intake work or precise emplacement. The base hull keeps its five crossings and its low drag.
These lines hold on every build of the hull and for every customer.
The page this sheet specifies, and the sheets beside it in the line.
The page this sheet specifies, with the pictures and the reasoning.
A first conversation needs the approach you have to know, the depth band, the current the work is timed to, and the job at the far end of the leg. Enquiries are screened before anything is discussed.
Not an offer. Enquiries are screened, international transfer is subject to Canadian government permits taken per shipment, the Tier 3 navigator and the emplace-and-retrieve cartridge carry export treatment of their own, and all designs, systems and technologies shown are patent pending.
